Process for cracking petroleum oil



Nov. 24, 1931 KlRSCHBRAUN 1,832,986

PROCESS FOR CRACKING PETROLEUM OIL Original Filed June 1, 1920 2 Sheets-Sheet 1v NOV. 24, 1931. K|RSHBRAUN Q I 1,832,986

PROCESS FOR CRACKING PETROLEUM OIL Original Filed June 1, 1920 2 Sheets-Sheet 2,

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process and apparatus for cracking petros Patented Nov. 24, 1931 UNITED STATES PATENT OFFICE LESTER KIRSCHBBAUN, OE LEONIA, NEW JERSEY, ASSIGNOB TO UNIVERSAL OII. PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A. CORPORATION OF SOUTH DAKOTA PROCESS FOR CRACKING PETROLEUM OIL Application filed llune 1, 1920, Serial No. 385,463. Renewed lay 28, 1928.

This invention relates to improvements in leum oil,'and refers more particularl to a continuous process adapted for use in the tube type of apparatus, although not necessarily limited thereto. In processes of this type the oil may first be sujected to a cracking temperature in a closed coil, as for example, 800 feet of two inch pipe, and then passed to an elongated reactlng chamber which may take the form of an 80-foot coil of twelve inch pipe. The process is operated under a suificient heating pressure to produce the desired cracking. Heretofore, much difliculty has been experienced in. keeping the outlet ends of the cracking coil and the vapor'chamberfree from carbon formation on the walls of the tubes, which results in clogging or burning out said tubes. It is. desirable to avoid, as far as possible, the vaporization of the oil in the smaller tubes which are seated in the fire zone, as where vapors are formed, carbon is recipitated. It is also desirable to continuously sweep the carbon out of the vapor chamber. I

The resent invention is designed to accomplis these objects, and in a simple and ,efietive manner. By means of the. present invention I also am able to use a lower heat in the crackin coil, which is highly desirable from the stan point of effective operation.

The essence of a the, invention consists in carrying the heated oil entirely (or practically so) through the vapor chambegwhmh is accomplished by-extendmg the two-mch pipe throu h ber throu Trout its len h. The Oll 1s then discharge at or near t e far end of the vapor chamber, and the residue drawn off from that end of the va or chamberfarthest remote from such discharge point. By this means, I am enabled to at all times provide a liquid body in the vapor chamber, and obviate the danger of the twelve-inch tubes going dry, or the residuum becoming too highly reduced.

I also, more or less, replenish theheat lost by vaporization in the twelve-inch p1 e which forms the vapor chamber, through t e interchange of heat from the oil in the two-inch I the bottom of the vapor champipe-which passes through the former,-thus n part, heating the residue, or partially converted material in the vaporchamber. The process utilizes the heat of the cracking zone more effectively because of the more uniform compensated for by the heat interchange which prevents undue dropping off of the temperature of the oil and vapors in the twelve-inch pipe. The cooling action of the residue on the oil in the two-inch pipe also tends to prevent the oil in the two-inch pipe from getting too hot and vaporizing, thus precipitatingcarbon and clogging up the small pipe.

In order that the invention may be more clearly understood, I have shown the accompanying drawings in which Fig. 1 is a somewhat diagrammatic plan view, and Fig. 2 is a side elevation of'my apparatus.

Referring to the drawings, 1 designates the furnace in which is mounted the cracking coil 2. Oil is delivered tocracking coil 2, connected by means of pump 3 to any suitable source of supply of charging stock. In suitable supports 4 is mounted the vapor or reacting chamber 5, which takes the form of a relatively large coil. The crackln coil 2 is provided with an extension 6. w ich is, or'may be, ofthe same or similar diameter to the coil,2, and extends through the vapor chamber 5. This extension 6 ,delivers the oil into the vapor chamber at the far .end of the latter at'the point 7 after, of course, being cooled by passage through the va or chamber 5. The vapor chamber is provided with a residue draw-01f 8 controlled by valve 9. It also has risers 10 leading to manifold 11, which in turn is connected to an aerial condenser 12. The aerial condenser 12 acts as a reflux condenser. That ortion .of the vapor which is not condense in the reflux condenser 12 passes throughwater condenser 13 into receiver 14. .The receiver 14 is provided with liquid draw-oil 15 and throttle valve 16. It also has a gas outlet 17 controlled by valve 18. If desired, a throttle 19 may be interposed in the coil 2 just before it enters the vapor chamber, and similarly, a throttle valve 20 may be interposed in the extension 6, nearer the discharge end of the latter. The use of the valves 19 and 20 will permit differential pressure being maintained on the system.

The following illustrative run may be given :Starting with gas oil of say 32 Baum gravity from a Kansas field; it may be heated to an oil temperature in the coil 2, of say 800 F. and subjected to a pressure in the coil 2, of 100 pounds. This pressure of 100 pounds may be carried through the system,

or not, as desired. Following the process in this way, some 60% of the oil may be converted into pressure distillate of say 51 Baum gravity. The object of the extension 6, which forms the salient feature of the invention, both in process and apparatus, has been heretofore set forth and need not be here repeated. It is to be understood that where pressure is maintained on the entire system this can readily be done by controlling the valves 16, 17, and 9. and opening the valves 19 and 20. In addition to the last. mentioned valves, a valve 21 may be interposed in the upper end of the aerial condenser just before it reaches the water condenser. This valve 21 will, of course, be wide open when a uniform pressure is maintained on the system.

I claim as my invention:

1. A continuous process of cracking hydrocarbon oil, consisting in passing the oil in a relatively small stream through a closed conduit in a heating zone wherein it is raised to a cracking temperature, in delivering the heated oil constituents into an enlarged reacting chamber, in maintaining a substan tially uniform temperature throughout the entire body of oil in said enlarged reacting chamber, by utilizing the heat contained in the heated oil constituents being delivered from the heating zone, by maintaining a heat interchange relationship between such heated oil constituents andothe body of oil in said reacting chamber but without permitting said heated oil constituents to come in physi cal contact with the body of oil in said reacting chamber for a substantial period after its admission thereto and in causing the oil, subsequent to its admission into said reactingchamber. to flow therethrough countercurrent to the flow of the heated oil constituents coming directly from the heating zone, and in maintaining a superatmospheric pressure on the oil in the heating zone and reacting chamber.

2. A continuous process of cracking hydrocarbon oil, consisting in passing the oil in a relatively small stream through a closed conduit disposed within a heating zone, wherein the oil is raised to a cracking temperature, in passing the heated oil, while in said relatively small stream, throughout substantially the entire length of an enlarged reaction chamber, in then admitting the oil from said relatively small'stream to said enlarged reaction chamber. to flow therethrough counter-current to the flow of the oil in said relatively small stream, to maintain the oil undergoing reaction in said enlarged reaction chamber at a substantially uniform temperature, in continuously taking oif products of conversion in vaporous form from said enlarged reaction chamber, and in maintaining a superatmospheric pressure on the oil undergoing conversion.

3. An improvement in a process for cracking hydrocarbon oil of the character in which the oil is heated in a coil and then transmitted to a reaction zone comprising causing the oil to pass in a confined stream throughout substantially the entire length of the reaction zone in heat interchange relation with oil accumulated in the reaction zone, thence admitting the oil to the reaction zone and during the o eration' of the process withdrawing resi ual oil from the reaction zone at a point remote from the point at which the oil is admitted to the reaction zone whereby the oil in said reaction zone flows countercurrent to said confined stream LESTER KIRSCHBRAUN. 

